It'll be undefined, but I now that you point it out I see it's a separate bug in play:

```shell
@importer = Facts::Importer.new(JSON.parse(File.read(File.expand_path(File.dirname(__FILE__) + '/test/unit/facts_debian.json')))['facts'])
=> #<Facts::Importer:0x007f3c387aa190 @facts={"processor3"=>"Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz", "productname"=>"IBM System x -[7870K4G]-"}>
```

```shell
@importer = Facts::Importer.new(JSON.parse(File.read(File.expand_path(File.dirname(__FILE__) + '/test/unit/facts_debian.json')))['facts'].delete("lsbdistcodename"))
=> #<Facts::Importer:0x007f3c38cb0950 @facts={}>
```

Note that the facts hash is empty.